The present invention generally relates to plumbing equipment, and more particularly problems associated with cleaning a plugged sewage drain line, for example, found in a residential and commercial buildings.
If a sewage drain line becomes obstructed in, for example, a residential or commercial building, the blockage is typically removed with a rod or cable inserted through a clean-out fitting located in the drain line above the obstruction. However, as soon as the clean-out plug is removed, backed-up sewage above the obstruction and clean-out fitting rapidly drains from the drain line through the fitting as a plug of the fitting is removed, often resulting in a spill that must be cleaned.
U.S. Pat. No. 2,241,560 to Schouler, U.S. Pat. No. 2,451,051 to Tubbs, U.S. Pat. No. 4,159,721 to Horter, U.S. Pat. No. 5,144,699 to Graham, and U.S. Published Patent Application No. 2005/0283890 to Schaaf are each concerned with draining a drain system prior to attempting to remove an obstruction. Schouler discloses a valve between a drain system and a clean-out plug, and through which sewage can drain to a hose. Tubbs also discloses the use of a valve between a drain system and a clean-out plug assembly, though with the intent that sewage is prevented from being drained prior to and during removal of an obstruction. Horter differs in that a drain hose is attached downstream from a clean-out plug of a drain system. Graham discloses a drain hose attached downstream of a valve that operates as a drain plug on a drain system. Schaaf discloses a drain valve that, while located downstream of a drain plug, enables a drain system to be drained without removing the plug.